Cyanin dye and process of making same.



- UNITED STATES PATENT OFFICE.

FAltBl/VERKE VORM. MlClS'llCli,

LUtlUS nurx'ixo, or uoeus'r- CYANIN DYE AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed February 1.6. 1904. Siliill No. 193.907. (Specimens) Be it known that l, E-uNs'r homo, lh. i).. cheinist,a citizen of the Empire of (lermany, residing at Hiichst-on-the-hlain, (lei-many, have invented certain new and useful lmprovements in the lVlanufacture of new Cyanin Dyestuffs, of which the following is a speci lication.

By cyanin is meant the known dyestuffs obtained by heating a mixture of quiuolin and lepidin-alkyl-iodid with caustic alkali. The magenta-red dyestuif obtained from quinaldin and quinolin-alkyl-iodid has also been called cyanin.

The cyanins render photographic plates sensitive to the yellow and red light, and inthe case of the blue lepidin-cyanins the sensitizing action extends even beyond the line (J in the red of the spectrum, whereas the red-violet quinaldincyanins sensitize only up to l) C in the orange.

The object of the present invention is to produce quinaldincyanins which will render the photographic plate more sensitive to red than do those known. For this purpose a mixture ofan alkyl halide of quinolin or of quinolin substituted in the meta or para posi tion (which, according to another nomenclature, is the 5 or 6 position) by alkyl or alkyloxyl and an alkyl halide of quinaldin similarly substituted or a mixture of an alkyl halide of quinolin substituted in the meta or para position by alkyl or alkyloxyl and an alkyl halide of quinaldin is heated with alkali in a suitable solvent, such as alcohol.

The following dyestuffs have been made according to this invention: quinaldin-metatoluquinolinalky-lcyanin, quinaldin-para-toluquinolinalkylcyanin, quinaldin para methoxy-quinoiinalkylcyanin, meta-toluquinaldinquinolinalkylcyanin, meta toluquinaldinmeta-toluquinolinalkylcyanin, meta-toluquinaldin-para-toluquinolinalkylcyanin, para-toluquinaldin quinolinalkylcyanin, para toluquinaldin meta toluquinolinalkylcyanin, para toluquinaldin para toluquinolinalky cyanin, para toluqu inald in para methoxy- (piinolinalkylcyanin, para-methoxyquinaldin para methoxyquinolincyanin, para ethoxyi'quinaldin para ethoxyquinolincyanin. Of these new dyestuffs are specially distinguished para-toluquinaldin-quinolinalkylcyanin, paraml mininaldin para toluquinol inallgvlcyanin,

l mra-toluquinaldin para -nu=ihox quinolinalkylcyuiiin, para metlroxyquiualiliu paramethoxyipiinolincyuniu, and para ethoxyl quinahlin-para-etlumyuuinoliu \'anin by their l rendering the photographic plate about twice to four times as sensitive to red as the hitherto known i uiualdinquinolincyuuin.

Example I: Thirtygramsof pura-tohmuinaldin-methyliodid and fifty-eight grams of para-toluquinolinmethyliodid are dissolved in eight hundred cubic centimeters of alcohol and the boiling solution is treated with 5.6 grams of caustic potash. The dyestui'l' is formed within a few minutes, and generally separates from the deep-red solution on cooling; but it may be necessary to add ether to precipitate the dyestufl, which is purified by recrystallization from water or alcohol. The pure dyestufi' forms dark-green brilliantneedles,soluble with some diliiculty in hot absolute alcohol, more readily soluble in hot water to a violet solution.

Example II: Thirty grains of meta-toluquinaldin-ethyl-iodid and sixty grams of metatoluquinolin-etl'iylioilid are dissolved in alcohol and the boiling solution is treated with 5.6 grams of caustic pot-ash. The dyestulf thus formed crystallizes when the solution is cold, and when purified forms beautiful crystals of coppery luster, soluble with some difiiculty in hot absolute alcohol, but more readily soluble in hot dilute alcohol to a red-violet solution. 1

It will be understood that the invention is not limited to the manufacture of the compounds named, for by the use of other derivatives of para and meta substituted quinolins and quinaldins or their derivatives or mixtures thereof like dyestuii's are obtainable.

Having now described my invention, what 1 claim is I 1. The process herein described of making new cyaniu dyestuffs, which consists in heati ing with alkalies in a suitable solven a mixi turc or two quiuolinium salts of which one contains u methyl in alpha position in the l coloron adding alkali; onshakingtheequeous mu-idin nucleus and one an alkyl linked to the benzene nucleus in the so-callenl 5 position.

2. As new products, the new eyanin dyestuffs obtained as herein set forth, being brilieut green to bronze-colored crystals, readily luele in hot Water, alcohol and chloroform with a, real-violet color, less soluble in cold water, insoluble in ether, benzene and ligroin; the aqueous solution becoming" deeolored on mhling diluted mineral acid, but reassumes its solution wit-h chloroform the latter absorbs the dyestuif so readily and completely as to decolor the aqueous solution.

In testimony that l claim the foregoing as my invention I have signed my name in presence of two subscribing wi'tnes es.

I, ERNS, KONIG.

Witnesses:

ALFRED BRIsBoIs, JOSEPH FLAOH. 

